[macOS] Revert breaking change to FlutterEngine public API (flutter/engine#22592)

engine/src/flutter/ci/licenses_golden/licenses_flutter

@@ -1054,8 +1054,6 @@ FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterExter
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTextureGL.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMouseCursorPlugin.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMouseCursorPlugin.mm
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterOpenGLRenderer.h
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterOpenGLRenderer.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterResizeSynchronizer.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterResizeSynchronizer.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterSurfaceManager.h

engine/src/flutter/shell/platform/darwin/common/framework/Headers/FlutterTexture.h

@@ -39,7 +39,7 @@ FLUTTER_EXPORT
 /**
  * Registers a `FlutterTexture` for usage in Flutter and returns an id that can be used to reference
  * that texture when calling into Flutter with channels. Textures must be registered on the
- * platform thread. On success returns the pointer to the registered texture, else returns 0.
+ * platform thread.
  */
 - (int64_t)registerTexture:(NSObject<FlutterTexture>*)texture;
 /**

engine/src/flutter/shell/platform/darwin/macos/BUILD.gn

@@ -54,8 +54,6 @@ source_set("flutter_framework_source") {
     "framework/Source/FlutterExternalTextureGL.mm",
     "framework/Source/FlutterMouseCursorPlugin.h",
     "framework/Source/FlutterMouseCursorPlugin.mm",
-    "framework/Source/FlutterOpenGLRenderer.h",
-    "framework/Source/FlutterOpenGLRenderer.mm",
     "framework/Source/FlutterResizeSynchronizer.h",
     "framework/Source/FlutterResizeSynchronizer.mm",
     "framework/Source/FlutterSurfaceManager.h",

engine/src/flutter/shell/platform/darwin/macos/framework/Headers/FlutterEngine.h

@@ -21,7 +21,7 @@
  * Coordinates a single instance of execution of a Flutter engine.
  */
 FLUTTER_EXPORT
-@interface FlutterEngine : NSObject <FlutterPluginRegistry>
+@interface FlutterEngine : NSObject <FlutterTextureRegistry, FlutterPluginRegistry>
 
 /**
  * Initializes an engine with the given viewController.

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterEngine.mm

@@ -10,7 +10,6 @@
 
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterDartProject_Internal.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTextureGL.h"
-#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterOpenGLRenderer.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterViewController_Internal.h"
 #import "flutter/shell/platform/embedder/embedder.h"
 
@@ -38,11 +37,42 @@ static FlutterLocale FlutterLocaleFromNSLocale(NSLocale* locale) {
  */
 - (void)sendUserLocales;
 
+/**
+ * Called by the engine to make the context the engine should draw into current.
+ */
+- (bool)engineCallbackOnMakeCurrent;
+
+/**
+ * Called by the engine to clear the context the engine should draw into.
+ */
+- (bool)engineCallbackOnClearCurrent;
+
+/**
+ * Called by the engine when the context's buffers should be swapped.
+ */
+- (bool)engineCallbackOnPresent;
+
+/**
+ * Called by the engine when framebuffer object ID is requested.
+ */
+- (uint32_t)engineCallbackOnFBO:(const FlutterFrameInfo*)info;
+
+/**
+ * Makes the resource context the current context.
+ */
+- (bool)engineCallbackOnMakeResourceCurrent;
+
 /**
  * Handles a platform message from the engine.
  */
 - (void)engineCallbackOnPlatformMessage:(const FlutterPlatformMessage*)message;
 
+/**
+ * Forwards texture copy request to the corresponding texture via |textureID|.
+ */
+- (BOOL)populateTextureWithIdentifier:(int64_t)textureID
+                        openGLTexture:(FlutterOpenGLTexture*)openGLTexture;
+
 /**
  * Requests that the task be posted back the to the Flutter engine at the target time. The target
  * time is in the clock used by the Flutter engine.
@@ -89,7 +119,7 @@ static FlutterLocale FlutterLocaleFromNSLocale(NSLocale* locale) {
 }
 
 - (id<FlutterTextureRegistry>)textures {
-  return _flutterEngine.openGLRenderer;
+  return _flutterEngine;
 }
 
 - (NSView*)view {
@@ -108,10 +138,38 @@ static FlutterLocale FlutterLocaleFromNSLocale(NSLocale* locale) {
 // Callbacks provided to the engine. See the called methods for documentation.
 #pragma mark - Static methods provided to engine configuration
 
+static bool OnMakeCurrent(FlutterEngine* engine) {
+  return [engine engineCallbackOnMakeCurrent];
+}
+
+static bool OnClearCurrent(FlutterEngine* engine) {
+  return [engine engineCallbackOnClearCurrent];
+}
+
+static bool OnPresent(FlutterEngine* engine) {
+  return [engine engineCallbackOnPresent];
+}
+
+static uint32_t OnFBO(FlutterEngine* engine, const FlutterFrameInfo* info) {
+  return [engine engineCallbackOnFBO:info];
+}
+
+static bool OnMakeResourceCurrent(FlutterEngine* engine) {
+  return [engine engineCallbackOnMakeResourceCurrent];
+}
+
 static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngine* engine) {
   [engine engineCallbackOnPlatformMessage:message];
 }
 
+static bool OnAcquireExternalTexture(FlutterEngine* engine,
+                                     int64_t texture_identifier,
+                                     size_t width,
+                                     size_t height,
+                                     FlutterOpenGLTexture* open_gl_texture) {
+  return [engine populateTextureWithIdentifier:texture_identifier openGLTexture:open_gl_texture];
+}
+
 #pragma mark -
 
 @implementation FlutterEngine {
@@ -121,12 +179,22 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
   // The project being run by this engine.
   FlutterDartProject* _project;
 
+  // The context provided to the Flutter engine for resource loading.
+  NSOpenGLContext* _resourceContext;
+
+  // The context that is owned by the currently displayed FlutterView. This is stashed in the engine
+  // so that the view doesn't need to be accessed from a background thread.
+  NSOpenGLContext* _mainOpenGLContext;
+
   // A mapping of channel names to the registered handlers for those channels.
   NSMutableDictionary<NSString*, FlutterBinaryMessageHandler>* _messageHandlers;
 
   // Whether the engine can continue running after the view controller is removed.
   BOOL _allowHeadlessExecution;
 
+  // A mapping of textureID to internal FlutterExternalTextureGL adapter.
+  NSMutableDictionary<NSNumber*, FlutterExternalTextureGL*>* _textures;
+
   // Pointer to the Dart AOT snapshot and instruction data.
   _FlutterEngineAOTData* _aotData;
 }
@@ -143,10 +211,10 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
 
   _project = project ?: [[FlutterDartProject alloc] init];
   _messageHandlers = [[NSMutableDictionary alloc] init];
+  _textures = [[NSMutableDictionary alloc] init];
   _allowHeadlessExecution = allowHeadlessExecution;
   _embedderAPI.struct_size = sizeof(FlutterEngineProcTable);
   FlutterEngineGetProcAddresses(&_embedderAPI);
-  _openGLRenderer = [[FlutterOpenGLRenderer alloc] initWithFlutterEngine:_engine];
 
   NSNotificationCenter* notificationCenter = [NSNotificationCenter defaultCenter];
   [notificationCenter addObserver:self
@@ -174,8 +242,17 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
     return NO;
   }
 
-  [_openGLRenderer attachToFlutterView:_viewController.flutterView];
-  const FlutterRendererConfig rendererConfig = [_openGLRenderer createRendererConfig];
+  const FlutterRendererConfig rendererConfig = {
+      .type = kOpenGL,
+      .open_gl.struct_size = sizeof(FlutterOpenGLRendererConfig),
+      .open_gl.make_current = (BoolCallback)OnMakeCurrent,
+      .open_gl.clear_current = (BoolCallback)OnClearCurrent,
+      .open_gl.present = (BoolCallback)OnPresent,
+      .open_gl.fbo_with_frame_info_callback = (UIntFrameInfoCallback)OnFBO,
+      .open_gl.fbo_reset_after_present = true,
+      .open_gl.make_resource_current = (BoolCallback)OnMakeResourceCurrent,
+      .open_gl.gl_external_texture_frame_callback = (TextureFrameCallback)OnAcquireExternalTexture,
+  };
 
   // TODO(stuartmorgan): Move internal channel registration from FlutterViewController to here.
 
@@ -274,6 +351,15 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
   }
 }
 
+- (void)setViewController:(FlutterViewController*)controller {
+  _viewController = controller;
+  _mainOpenGLContext = controller.flutterView.openGLContext;
+  if (!controller && !_allowHeadlessExecution) {
+    [self shutDownEngine];
+    _resourceContext = nil;
+  }
+}
+
 - (id<FlutterBinaryMessenger>)binaryMessenger {
   // TODO(stuartmorgan): Switch to FlutterBinaryMessengerRelay to avoid plugins
   // keeping the engine alive.
@@ -286,6 +372,17 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
   return _engine != nullptr;
 }
 
+- (NSOpenGLContext*)resourceContext {
+  if (!_resourceContext) {
+    NSOpenGLPixelFormatAttribute attributes[] = {
+        NSOpenGLPFAColorSize, 24, NSOpenGLPFAAlphaSize, 8, 0,
+    };
+    NSOpenGLPixelFormat* pixelFormat = [[NSOpenGLPixelFormat alloc] initWithAttributes:attributes];
+    _resourceContext = [[NSOpenGLContext alloc] initWithFormat:pixelFormat shareContext:nil];
+  }
+  return _resourceContext;
+}
+
 - (void)updateDisplayConfig {
   if (!_engine) {
     return;
@@ -364,6 +461,37 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
   _embedderAPI.UpdateLocales(_engine, flutterLocaleList.data(), flutterLocaleList.size());
 }
 
+- (bool)engineCallbackOnMakeCurrent {
+  if (!_mainOpenGLContext) {
+    return false;
+  }
+  [_mainOpenGLContext makeCurrentContext];
+  return true;
+}
+
+- (uint32_t)engineCallbackOnFBO:(const FlutterFrameInfo*)info {
+  CGSize size = CGSizeMake(info->size.width, info->size.height);
+  return [_viewController.flutterView frameBufferIDForSize:size];
+}
+
+- (bool)engineCallbackOnClearCurrent {
+  [NSOpenGLContext clearCurrentContext];
+  return true;
+}
+
+- (bool)engineCallbackOnPresent {
+  if (!_mainOpenGLContext) {
+    return false;
+  }
+  [self.viewController.flutterView present];
+  return true;
+}
+
+- (bool)engineCallbackOnMakeResourceCurrent {
+  [self.resourceContext makeCurrentContext];
+  return true;
+}
+
 - (void)engineCallbackOnPlatformMessage:(const FlutterPlatformMessage*)message {
   NSData* messageData = [NSData dataWithBytesNoCopy:(void*)message->message
                                              length:message->message_size
@@ -490,6 +618,31 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
   return [[FlutterEngineRegistrar alloc] initWithPlugin:pluginName flutterEngine:self];
 }
 
+#pragma mark - FlutterTextureRegistrar
+
+- (BOOL)populateTextureWithIdentifier:(int64_t)textureID
+                        openGLTexture:(FlutterOpenGLTexture*)openGLTexture {
+  return [_textures[@(textureID)] populateTexture:openGLTexture];
+}
+
+- (int64_t)registerTexture:(id<FlutterTexture>)texture {
+  FlutterExternalTextureGL* FlutterTexture =
+      [[FlutterExternalTextureGL alloc] initWithFlutterTexture:texture];
+  int64_t textureID = [FlutterTexture textureID];
+  _embedderAPI.RegisterExternalTexture(_engine, textureID);
+  _textures[@(textureID)] = FlutterTexture;
+  return textureID;
+}
+
+- (void)textureFrameAvailable:(int64_t)textureID {
+  _embedderAPI.MarkExternalTextureFrameAvailable(_engine, textureID);
+}
+
+- (void)unregisterTexture:(int64_t)textureID {
+  _embedderAPI.UnregisterExternalTexture(_engine, textureID);
+  [_textures removeObjectForKey:@(textureID)];
+}
+
 #pragma mark - Task runner integration
 
 - (void)postMainThreadTask:(FlutterTask)task targetTimeInNanoseconds:(uint64_t)targetTime {

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterEngine_Internal.h

@@ -6,7 +6,6 @@
 
 #import <Cocoa/Cocoa.h>
 
-#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterOpenGLRenderer.h"
 #include "flutter/shell/platform/embedder/embedder.h"
 
 @interface FlutterEngine ()
@@ -17,10 +16,10 @@
 @property(nonatomic, readonly) BOOL running;
 
 /**
- * Provides the renderer config needed to initialize the engine and also handles external texture
- * management.
+ * The resource context used by the engine for texture uploads. FlutterViews associated with this
+ * engine should be created to share with this context.
  */
-@property(nonatomic, readonly, nonnull) FlutterOpenGLRenderer* openGLRenderer;
+@property(nonatomic, readonly, nullable) NSOpenGLContext* resourceContext;
 
 /**
  * Function pointers for interacting with the embedder.h API.

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterOpenGLRenderer.h

@@ -1,85 +0,0 @@
-// Copyright 2013 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#import <Cocoa/Cocoa.h>
-
-#import "flutter/shell/platform/darwin/macos/framework/Headers/FlutterEngine.h"
-#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterView.h"
-#import "flutter/shell/platform/embedder/embedder.h"
-
-NS_ASSUME_NONNULL_BEGIN
-
-/**
- * Provides the renderer config needed to initialize the embedder engine and also handles external
- * texture management. This is initialized during FlutterEngine creation and then attached to the
- * FlutterView once the FlutterViewController is initializer.
- */
-@interface FlutterOpenGLRenderer : NSObject <FlutterTextureRegistry>
-
-/**
- * The resource context used by the engine for texture uploads. FlutterViews associated with this
- * engine should be created to share with this context.
- */
-@property(nonatomic, readonly, nullable) NSOpenGLContext* resourceContext;
-
-/**
- * The main OpenGL which will be used for rendering contents to the FlutterView.
- */
-@property(readwrite, nonatomic, nonnull) NSOpenGLContext* openGLContext;
-
-/**
- * Intializes the renderer with the given FlutterEngine.
- */
-- (instancetype)initWithFlutterEngine:(FLUTTER_API_SYMBOL(FlutterEngine))engine;
-
-/**
- * Attaches to the FlutterView and sets up the renderers main OpenGL context.
- */
-- (void)attachToFlutterView:(FlutterView*)view;
-
-/**
- * Called by the engine to make the context the engine should draw into current.
- */
-- (bool)makeCurrent;
-
-/**
- * Called by the engine to clear the context the engine should draw into.
- */
-- (bool)clearCurrent;
-
-/**
- * Called by the engine when the context's buffers should be swapped.
- */
-- (bool)present;
-
-/**
- * Called by the engine when framebuffer object ID is requested.
- */
-- (uint32_t)getFBO:(const FlutterFrameInfo*)info;
-
-/**
- * Makes the resource context the current context.
- */
-- (bool)makeResourceCurrent;
-
-/**
- * Called by the engine to unset the resource context.
- */
-- (void)clearResourceContext;
-
-/**
- * Populates the texture registry with the provided openGLTexture.
- */
-- (BOOL)populateTextureWithIdentifier:(int64_t)textureID
-                        openGLTexture:(FlutterOpenGLTexture*)openGLTexture;
-
-/**
- * Creates a FlutterRendererConfig that renders using OpenGL context(s) held
- * by this class.
- */
-- (FlutterRendererConfig)createRendererConfig;
-
-@end
-
-NS_ASSUME_NONNULL_END

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterOpenGLRenderer.mm

@@ -1,187 +0,0 @@
-// Copyright 2013 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterOpenGLRenderer.h"
-#include "flutter/shell/platform/darwin/macos/framework/Source/FlutterView.h"
-#include "flutter/shell/platform/embedder/embedder.h"
-
-#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterEngine_Internal.h"
-#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTextureGL.h"
-
-#pragma mark - Static methods for openGL callbacks that require the engine.
-
-static bool OnMakeCurrent(FlutterEngine* engine) {
-  return [engine.openGLRenderer makeCurrent];
-}
-
-static bool OnClearCurrent(FlutterEngine* engine) {
-  return [engine.openGLRenderer clearCurrent];
-}
-
-static bool OnPresent(FlutterEngine* engine) {
-  return [engine.openGLRenderer present];
-}
-
-static uint32_t OnFBO(FlutterEngine* engine, const FlutterFrameInfo* info) {
-  return [engine.openGLRenderer getFBO:info];
-}
-
-static bool OnMakeResourceCurrent(FlutterEngine* engine) {
-  return [engine.openGLRenderer makeResourceCurrent];
-}
-
-static bool OnAcquireExternalTexture(FlutterEngine* engine,
-                                     int64_t textureIdentifier,
-                                     size_t width,
-                                     size_t height,
-                                     FlutterOpenGLTexture* openGlTexture) {
-  return [engine.openGLRenderer populateTextureWithIdentifier:textureIdentifier
-                                                openGLTexture:openGlTexture];
-}
-
-#pragma mark - FlutterOpenGLRenderer implementation.
-
-@implementation FlutterOpenGLRenderer {
-  // The embedding-API-level engine object.
-  FLUTTER_API_SYMBOL(FlutterEngine) _engine;
-
-  FlutterView* _flutterView;
-
-  // The context that is owned by the currently displayed FlutterView. This is stashed
-  // in the renderer so that the view doesn't need to be accessed from a background thread.
-  NSOpenGLContext* _openGLContext;
-
-  // The context provided to the Flutter engine for resource loading.
-  NSOpenGLContext* _resourceContext;
-
-  // A mapping of textureID to internal FlutterExternalTextureGL adapter.
-  NSMutableDictionary<NSNumber*, FlutterExternalTextureGL*>* _textures;
-
-  FlutterEngineProcTable _embedderAPI;
-}
-
-- (instancetype)initWithFlutterEngine:(FLUTTER_API_SYMBOL(FlutterEngine))engine {
-  self = [super init];
-  if (self) {
-    _engine = engine;
-    _textures = [[NSMutableDictionary alloc] init];
-  }
-  return self;
-}
-
-- (void)attachToFlutterView:(FlutterView*)view {
-  _flutterView = view;
-}
-
-- (bool)makeCurrent {
-  if (!_openGLContext) {
-    return false;
-  }
-  [_openGLContext makeCurrentContext];
-  return true;
-}
-
-- (bool)clearCurrent {
-  [NSOpenGLContext clearCurrentContext];
-  return true;
-}
-
-- (bool)present {
-  if (!_openGLContext) {
-    return false;
-  }
-  [_flutterView present];
-  return true;
-}
-
-- (uint32_t)getFBO:(const FlutterFrameInfo*)info {
-  CGSize size = CGSizeMake(info->size.width, info->size.height);
-  return [_flutterView frameBufferIDForSize:size];
-}
-
-- (NSOpenGLContext*)resourceContext {
-  if (!_resourceContext) {
-    NSOpenGLPixelFormatAttribute attributes[] = {
-        NSOpenGLPFAColorSize, 24, NSOpenGLPFAAlphaSize, 8, 0,
-    };
-    NSOpenGLPixelFormat* pixelFormat = [[NSOpenGLPixelFormat alloc] initWithAttributes:attributes];
-    _resourceContext = [[NSOpenGLContext alloc] initWithFormat:pixelFormat shareContext:nil];
-  }
-  return _resourceContext;
-}
-
-- (NSOpenGLContext*)openGLContext {
-  if (!_openGLContext) {
-    NSOpenGLContext* shareContext = [self resourceContext];
-    _openGLContext = [[NSOpenGLContext alloc] initWithFormat:shareContext.pixelFormat
-                                                shareContext:shareContext];
-  }
-  return _openGLContext;
-}
-
-- (bool)makeResourceCurrent {
-  [self.resourceContext makeCurrentContext];
-  return true;
-}
-
-- (void)clearResourceContext {
-  _resourceContext = nil;
-}
-
-#pragma mark - FlutterTextureRegistrar
-
-- (BOOL)populateTextureWithIdentifier:(int64_t)textureID
-                        openGLTexture:(FlutterOpenGLTexture*)openGLTexture {
-  return [_textures[@(textureID)] populateTexture:openGLTexture];
-}
-
-- (int64_t)registerTexture:(id<FlutterTexture>)texture {
-  FlutterExternalTextureGL* FlutterTexture =
-      [[FlutterExternalTextureGL alloc] initWithFlutterTexture:texture];
-  int64_t textureID = [FlutterTexture textureID];
-  auto success = _embedderAPI.RegisterExternalTexture(_engine, textureID);
-  if (success == FlutterEngineResult::kSuccess) {
-    _textures[@(textureID)] = FlutterTexture;
-    return textureID;
-  } else {
-    NSLog(@"Unable to register the texture with id: %lld.", textureID);
-    return 0;
-  }
-}
-
-- (void)textureFrameAvailable:(int64_t)textureID {
-  auto success = _embedderAPI.MarkExternalTextureFrameAvailable(_engine, textureID);
-  if (success != FlutterEngineResult::kSuccess) {
-    NSLog(@"Unable to mark texture with id %lld as available.", textureID);
-  }
-}
-
-- (void)unregisterTexture:(int64_t)textureID {
-  auto success = _embedderAPI.UnregisterExternalTexture(_engine, textureID);
-  if (success == FlutterEngineResult::kSuccess) {
-    [_textures removeObjectForKey:@(textureID)];
-  } else {
-    NSLog(@"Unable to unregister texture with id: %lld.", textureID);
-  }
-}
-
-#pragma mark - Helper methods to create rendering config for embedder.
-
-- (FlutterRendererConfig)createRendererConfig {
-  const FlutterRendererConfig rendererConfig = {
-      .type = kOpenGL,
-      .open_gl.struct_size = sizeof(FlutterOpenGLRendererConfig),
-      .open_gl.make_current = reinterpret_cast<BoolCallback>(OnMakeCurrent),
-      .open_gl.clear_current = reinterpret_cast<BoolCallback>(OnClearCurrent),
-      .open_gl.present = reinterpret_cast<BoolCallback>(OnPresent),
-      .open_gl.fbo_with_frame_info_callback = reinterpret_cast<UIntFrameInfoCallback>(OnFBO),
-      .open_gl.fbo_reset_after_present = true,
-      .open_gl.make_resource_current = reinterpret_cast<BoolCallback>(OnMakeResourceCurrent),
-      .open_gl.gl_external_texture_frame_callback =
-          reinterpret_cast<TextureFrameCallback>(OnAcquireExternalTexture),
-  };
-  return rendererConfig;
-}
-
-@end

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterView.h

@@ -20,14 +20,19 @@
  */
 @interface FlutterView : NSView
 
+/**
+ * The OpenGL context of backing surface.
+ */
+@property(readwrite, nonatomic, nonnull) NSOpenGLContext* openGLContext;
+
 - (nullable instancetype)initWithFrame:(NSRect)frame
-                           mainContext:(nonnull NSOpenGLContext*)mainContext
+                          shareContext:(nonnull NSOpenGLContext*)shareContext
                        reshapeListener:(nonnull id<FlutterViewReshapeListener>)reshapeListener
     NS_DESIGNATED_INITIALIZER;
 
-- (nullable instancetype)initWithMainContext:(nonnull NSOpenGLContext*)mainContext
-                             reshapeListener:
-                                 (nonnull id<FlutterViewReshapeListener>)reshapeListener;
+- (nullable instancetype)initWithShareContext:(nonnull NSOpenGLContext*)shareContext
+                              reshapeListener:
+                                  (nonnull id<FlutterViewReshapeListener>)reshapeListener;
 
 - (nullable instancetype)initWithFrame:(NSRect)frameRect
                            pixelFormat:(nullable NSOpenGLPixelFormat*)format NS_UNAVAILABLE;

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterView.mm

@@ -15,29 +15,30 @@
   __weak id<FlutterViewReshapeListener> _reshapeListener;
   FlutterResizeSynchronizer* _resizeSynchronizer;
   FlutterSurfaceManager* _surfaceManager;
-  NSOpenGLContext* _openGLContext;
 }
 
 @end
 
 @implementation FlutterView
 
-- (instancetype)initWithMainContext:(NSOpenGLContext*)mainContext
-                    reshapeListener:(id<FlutterViewReshapeListener>)reshapeListener {
-  return [self initWithFrame:NSZeroRect mainContext:mainContext reshapeListener:reshapeListener];
+- (instancetype)initWithShareContext:(NSOpenGLContext*)shareContext
+                     reshapeListener:(id<FlutterViewReshapeListener>)reshapeListener {
+  return [self initWithFrame:NSZeroRect shareContext:shareContext reshapeListener:reshapeListener];
 }
 
 - (instancetype)initWithFrame:(NSRect)frame
-                  mainContext:(NSOpenGLContext*)mainContext
+                 shareContext:(NSOpenGLContext*)shareContext
               reshapeListener:(id<FlutterViewReshapeListener>)reshapeListener {
   self = [super initWithFrame:frame];
   if (self) {
-    _openGLContext = mainContext;
+    self.openGLContext = [[NSOpenGLContext alloc] initWithFormat:shareContext.pixelFormat
+                                                    shareContext:shareContext];
+
     [self setWantsLayer:YES];
 
     _resizeSynchronizer = [[FlutterResizeSynchronizer alloc] initWithDelegate:self];
     _surfaceManager = [[FlutterSurfaceManager alloc] initWithLayer:self.layer
-                                                     openGLContext:_openGLContext];
+                                                     openGLContext:self.openGLContext];
 
     _reshapeListener = reshapeListener;
   }
@@ -45,7 +46,7 @@
 }
 
 - (void)resizeSynchronizerFlush:(FlutterResizeSynchronizer*)synchronizer {
-  MacOSGLContextSwitch context_switch(_openGLContext);
+  MacOSGLContextSwitch context_switch(self.openGLContext);
   glFlush();
 }
 

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterViewController.mm

@@ -239,13 +239,13 @@ static void CommonInit(FlutterViewController* controller) {
 }
 
 - (void)loadView {
-  NSOpenGLContext* mainContext = _engine.openGLRenderer.openGLContext;
-  if (!mainContext) {
-    NSLog(@"Unable to create FlutterView; no GL context available.");
+  NSOpenGLContext* resourceContext = _engine.resourceContext;
+  if (!resourceContext) {
+    NSLog(@"Unable to create FlutterView; no resource context available.");
     return;
   }
-  FlutterView* flutterView = [[FlutterView alloc] initWithMainContext:mainContext
-                                                      reshapeListener:self];
+  FlutterView* flutterView = [[FlutterView alloc] initWithShareContext:resourceContext
+                                                       reshapeListener:self];
   self.view = flutterView;
 }